Atomic Structure

Question 1

Chlorine has two isotopes
Cl³⁵₁₇ and Cl³⁷₁₇

Explain why these two isotopes have different mass numbers

[2 marks]

Answer 1

The isotopes have a different number of neutrons

Cl³⁵₁₇ has 18 neutrons and Cl³⁷₁₇ has 20 nuetrons

1) say the answer then 2) USE the FIGURE (basically)

Question 2

The relative formula mass of chlorine is 35.5

Explain why this is not a whole number

1 mark

Answer 2

35.5 is an average of the isotope abundance of chlorine